1985, and was a frequent visitor to the Indian Statistical Institute, Calcutta. The period around 1960 seems to have been particularly important and fruitful for Berge. Through the book Théorie des graphes et ses applications he had established a mathematical name for himself. In 1959 he attended the first graph theory conference ever in Dobogókő, Hungary, and met the Hungarian graph theorists. He published a survey paper on graph coloring, where he introduced the ideas that soon led to perfect graphs. In March 1960 he talked about this at a meeting in Halle in East Germany. In November of the same year, he was one of the ten founding members of the OuLiPo (Ouvroir de Litt´erature Potentiel). And in 1961, with his friend and colleague Marcel-Paul Schützenberger, he initiated the Séminaire sur les problèmes combinatoires at the University of Paris (which later became the Équipe combinatoire du CNRS). At the same time, Berge achieved success as a sculptor. In 1994 Berge wrote a 'mathematical' murder mystery for Oulipo. In this short story, Who killed the Duke of Densmore (1995), the Duke of Densmore has been murdered by one of his six mistresses, and Sherlock Holmes and Dr. Watson are summoned to solve the case. Watson is sent by Holmes to the Duke's castle but, on his return, the information he conveys to Holmes is very muddled. Holmes uses the information that Watson gives him to construct a graph. He then applies a theorem of György Hajós to the graph which produces the name of the murderer. Other clever contributions of Berge to Oulipo are described in . Another of Berge's interests was in art and sculpture. He described his early sculptures, made in part from stones found in the river Seine, in his book Sculptures multipètres (1962). Bjarne Toft writes: Mathematical contributions Berge wrote five books, on game theory (1957), graph theory and its applications (1958), topological spaces (1959), principles of combinatorics (1968) and hypergraphs (1970), each being translated in several languages. These books helped bring the subjects of graph theory and combinatorics out of disrepute by highlighting the successful practical applications of the subjects. He is particularly remembered for two conjectures on perfect graphs that he made in the early 1960s but were not proved until significantly later: A graph is perfect if and only if its complement is perfect, proven by László Lovász in 1972 and now known